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A224138 Number of 7 X n 0..1 arrays with rows nondecreasing and antidiagonals unimodal. 1
128, 2187, 9688, 25047, 52581, 101412, 186348, 329167, 561329, 927323, 1488515, 2327716, 3554534, 5311574, 7781550, 11195373, 15841279, 22075061, 30331469, 41136842, 55123036, 73042712, 95786048, 124398939, 160102749, 204315679 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 7 of A224133.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = (4/315)*n^7 + (1/5)*n^6 + (112/45)*n^5 + (461/24)*n^4 + (19267/180)*n^3 + (50171/120)*n^2 + (463243/420)*n - 511 for n>5.

Conjectures from Colin Barker, Aug 27 2018: (Start)

G.f.: x*(128 + 1163*x - 4224*x^2 + 1611*x^3 + 9957*x^4 - 14526*x^5 + 3960*x^6 + 4357*x^7 - 1401*x^8 - 1818*x^9 + 659*x^10 + 353*x^11 - 155*x^12) / (1 - x)^8.

a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8) for n>13.

(End)

EXAMPLE

Some solutions for n=3:

..0..0..1....1..1..1....0..1..1....0..0..0....1..1..1....0..0..0....0..1..1

..0..1..1....0..0..1....1..1..1....1..1..1....1..1..1....0..0..0....0..0..1

..0..0..1....0..0..1....1..1..1....1..1..1....0..0..1....0..1..1....0..1..1

..0..0..0....0..0..1....0..0..0....0..1..1....0..0..0....1..1..1....0..0..0

..0..1..1....0..0..1....0..1..1....0..0..0....0..0..0....0..0..1....0..1..1

..0..0..0....0..1..1....0..0..1....0..0..1....0..0..0....0..1..1....0..0..0

..0..0..1....0..0..1....0..0..0....0..0..0....1..1..1....0..0..0....0..0..0

CROSSREFS

Cf. A224133.

Sequence in context: A195594 A321831 A223954 * A331198 A250365 A017678

Adjacent sequences:  A224135 A224136 A224137 * A224139 A224140 A224141

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 31 2013

STATUS

approved

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Last modified January 23 21:56 EST 2022. Contains 350515 sequences. (Running on oeis4.)